DENVER - It's a new race for the White House. Mitt Romney changed the game with his aggressive, confident performance in Wednesday's Denver debate, and erased the specter of doom that has dogged his campaign for weeks.

President Barack Obama's forces had hinted that all they needed was one good punch to knock out Romney after the Republican spent the summer and early fall stumbling.

Instead, the Romney whom viewers saw Wednesday was the one his friends have long known: the conversational, smart, decent-on-his-feet guy, eager to defend his views vigorously and declaring that his yen for cutting taxes and changing seniors' health care systems made sense.

An even cursory dig into the details of those Romney plans - details that are often elusive - will continue to give Democrats ammunition against him, and Obama could recover quickly by relentlessly pressing Romney on those points.

Obama also can take solace in history, which shows that incumbent presidents often falter in first debates - see George W. Bush in 2004 or Ronald Reagan in 1984 - and then come back and win.

But a strong performance by a challenger does reshape the race in several ways.

Romney donors and grass-roots workers get a fresh, badly needed shot of momentum and energy.

Wavering voters also pay fresh attention. The undecideds, a small but crucial sliver of the electorate, tend to be people who rarely tune in to politics but will notice at least part of a debate.

Advertisement

Such voters are usually younger, without the kinds of steady political allegiances that ultimately drive many voters to reluctantly back their parties' candidates.

Another group of voters to watch is the persuadables, folks who say they'll vote one way but still can be swayed. They're the ones who say they'll go with Obama because they don't like Romney or vice versa.

A bravura debate performance can change that equation. Suddenly, they may have someone to vote for, not against.

A debate such as Wednesday's spurs other changes. The culture takes notice. A Pew Research Center poll recently found that people thought Clint Eastwood's encounter with an empty chair at the Republican National Convention was the event's highlight, not Romney's acceptance speech.

In the coming days, should Obama's performance get lampooned on "The Daily Show," "Saturday Night Live," Leno and Letterman, it could create an impression that lasts, an image of the president as too academic, too cold, uneasy with being challenged.

"Obama's life and his operating style had been built around avoiding confrontation," Bob Woodward wrote in his book "The Price of Politics," as he described the president's frosty relationship with Democratic congressional leaders.

That style was apparent Wednesday. Toward the end of the debate, Romney, known as a friendly, easy conversationalist, offered a rambling but upbeat assessment of how he would govern.

"As president I will sit on day one - actually the day after I get elected - I'll sit down with leaders, the Democratic leaders as well as the Republican leaders, and continue, as we did in my state, we met every Monday for a couple of hours, talked about the issues and the challenges in the - in the - in our state in that case," he said.

Obama gave a dismissive look and quipped that Romney is "going to have a busy first day, because he's also going to repeal Obamacare, which will not be very popular among Democrats as you're sitting down with them."

Then he got lofty, trying to invoke that above-the-battle tone that served him so well four years ago. "But look," the president said, "my philosophy has been, I will take ideas from anybody." Then he launched into a long description of policies.

That style is going to be harder to sell at the next presidential debate, Oct. 16 in Hempstead, N.Y., where the stakes have been instantly ratcheted up.

Speculation will focus on whether Obama can look and act comfortable, whether he can make the eye contact with the audience he seemed to lack Wednesday. The town hall format will feature audience members asking questions about foreign or domestic policy.

Campaign senior adviser David Axelrod conceded that Romney "is very good on the attack. I was not at all surprised." He said the Obama strategy wouldn't change, that when voters reflected on the two candidates, "they'll remember a thoughtful, honest leader debating against someone else trying to sell implausible theories."

Axelrod ticked off the theories: Romney's vow to cut income taxes 20 percent and claiming that the budget deficit wouldn't balloon, yet failing to offer details. Or his plan to offer seniors federal help to buy Medicare or private coverage after 2023, a plan that Obama says would wreck Medicare.

Any such logic Thursday was overwhelmed by the grim mood. After the debate, twice as many Romney surrogates appeared to talk to reporters. The Obama people left the scene quickly. A CNN/ORC International poll of 430 people just after the debate found that 67 percent thought Romney did a better job. CBS polled uncommitted voters, and they gave Romney a 46-22 percent edge.

None of this means that Romney is about to surge. Democratic nominee Walter Mondale thought he had momentum after the first 1984 debate, when Reagan appeared vague and confused, raising questions about whether, at 73, he could still do the job. But Reagan recovered in the next debate two weeks later and went on to win 49 states.

What Romney's showing does is get the undecideds and persuadables, most of whom are struggling for economic security, to take another look. Obama's approval numbers have languished around 50 percent, consumer confidence remains sluggish, unemployment is stuck over 8 percent and the economy grew at a miserable 1.3 percent pace last quarter.

Romney, saddled with his own troubles, has been unable to crack the 47 percent mark in most polls. He has been dogged by his comments about how 47 percent of Americans are "victims" dependent on government, on his refusal to release 10 years of tax returns, his investments while running the Bain Capital private equity firm and more.

But on Thursday, it's Obama who's on the defensive. "This was the first time the president really had to answer for his record," Romney senior strategist Stuart Stevens said.

ODESSA, Texas (AP) — A West Texas man has been charged with impersonating an officer by using sirens and flashing lights to skip to the head of the drive-thru line at a fast-food restaurant. Full Story

Sufjan Stevens, "Carrie & Lowell" (Asthmatic Kitty) Plucked strings and pulsing keyboards dominate the distinctive arrangements on Sufjan Stevens' latest album, and in the absence of a rhythm section, they serve to keep time. Full Story